Re varnishing with Epifanes

[davidpbo]

Fortunately we have limited external woodwork on our 23ft boat. Mostly varnished with polyurethane varnish. Last year we did a replacement rail on the boarding platform with Epifanes which has lasted much better so this year we are using it on everything. Do I need to strip back to bare wood or remove loose and heavily abraid? Some of it is relatively easy to sand but I don't want to go through a veneer again.

If stripping back to bare wood, the boards for the boarding platform are awkward to sand with gaps in between, I was contemplating using paint stripper, comments please?

Also we have some spilt and overpaint of old varnish by the grab rails on fibreglass, again can I use paint stripper on this or will it damage the fibreglass?

 

[ghostlymoron]

Fortunately we have limited external woodwork on our 23ft boat. Mostly varnished with polyurethane varnish. Last year we did a replacement rail on the boarding platform with Epifanes which has lasted much better so this year we are using it on everything. Do I need to strip back to bare wood or remove loose and heavily abraid? Some of it is relatively easy to sand but I don't want to go through a veneer again.

If stripping back to bare wood, the boards for the boarding platform are awkward to sand with gaps in between, I was contemplating using paint stripper, comments please?

Also we have some spilt and overpaint of old varnish by the grab rails on fibreglass, again can I use paint stripper on this or will it damage the fibreglass?

Normal paint stripper like Nitromors can degrade fibreglass but there are fibreglass friendly paint strippers available.

 

[davidpbo]

Normal paint stripper like Nitromors can degrade fibreglass but there are fibreglass friendly paint strippers available.

Do you know any names please?
I have some Langlow stripper 20+ years old which does not seem to caustic but seems only to be available to trade now not that that is insurmountable.

 

[Tranona]

Old varnish on GRP is difficult to move, but you can try paint stripper. I use the basic stuff from B&Q, not as harsh as the older style, but in my experience effective. apply, leave to bubble then scrape off. wash down with white spirit. May need more than one go, but minimal sanding required after stripping. Conventional yacht varnishes are herd work on bits of wood trim on a GRP boat. As you have discovered they barely last a year and need regular refinishing. Trend now is to use wood stains such as International Woodskin. Although they do not give a high gloss finish they are easy to apply and will last several year with the occasional rub down and recoat.

 

[Pye_End]

What wood is it? If teak I agree with Tranona - ie go for Woodskin or Sikkens Cetol.

Epiphanes will happily sit on a polyurethane - the decision to strip back to wood is mainly aesthetics.

Paint stripper and GRP - should be fine, so long as you are cleaning/washing off in minutes rather than days.

 

[superheat6k]

For the stripper try Dilunett (smells like a blocked drain though).

When applying Epifanes start with a very dilute solution with their own thinner, around 25%, then gradually build up to 90% over ~6 layers. A lot of effort but the end result is fantastic. Lightly sand then Wipe down with a tack cloth before each coat.

The very thin layers allows the Epifanes to penetrate deep into the grain, rather than just sitting on the outer surface, making for far more effective adhesion, and hence longevity.

I personally would make every effort to get back to bare wood.

However, for outside wood I am a fan of Deks Olye - D1 saturate several coats over several hours wet on wet, then ~6 coats D2, each allowed to dry for a day.

 

[davidpbo]

For the stripper try Dilunett (smells like a blocked drain though).

When applying Epifanes start with a very dilute solution with their own thinner, around 25%, then gradually build up to 90% over ~6 layers. A lot of effort but the end result is fantastic. Lightly sand then Wipe down with a tack cloth before each coat.

The very thin layers allows the Epifanes to penetrate deep into the grain, rather than just sitting on the outer surface, making for far more effective adhesion, and hence longevity.

I personally would make every effort to get back to bare wood.

However, for outside wood I am a fan of Deks Olye - D1 saturate several coats over several hours wet on wet, then ~6 coats D2, each allowed to dry for a day.

Thanks for the reply but it is not going to get that sort of treatment, too small an area, although I have sanded back to bare wood. I would do the first coat with thinners if I had some, anyone know what it is, I have acetone, cellulose thinners, hammerite thinners, white spirit etc.